IR sensor fits on a contact lens

Apr. 30, 2014 - 02:24PM
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University of Michigan researchers have developed an infrared sensor that can be inserted into a contact lens.

“We can make the entire design super-thin,” said Zhaohui Zhong, an assistant professor of electrical engineering and computer science, in a university press release. "It can be stacked on a contact lens or integrated with a cell phone. "

The sensor doesn't require bulky cooling equipment. Instead it uses graphene - a single layer of carbon atoms - which can sense visible and ultraviolet light. But until now, graphene hasn’t been viable for infrared detection because it can’t capture enough light to generate a detectable electrical signal, said Univ. of Michigan.

So, researchers used a different approach. Rather than trying to directly measure the electrons that are freed when light hits the graphene, they amplified the signal by looking instead at how the light-induced electrical charges in the graphene affect a nearby current.

By measuring the change in current, the team could deduce the brightness of the light hitting the graphene," the university said. "The new approach allowed the sensitivity of a room-temperature graphene device to compete with that of cooled mid-infrared detectors for the first time."